Folding armchair



FIG. 1 is a perspective view of a folding armchair showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a top plan view thereof;

FIG. 5 is a bottom plan view thereof; and,

FIG. 6 is a left side elevational view thereof, the right side being a mirror image. 

CLAIM The ornamental design for a folding armchair, as shown and described. 